Photovoltaic solar cells tap the sun's limitless energy. Tapping such a limitless energy source could remedy the world's many energy dilemmas. Photovoltaic cells, for example, absorb energy from light and convert the absorbed energy to an electrical current. As shown in FIG. 1, in a conventional (e.g. planar) single-junction solar cell 100, a light photon 105 from sun 110 impinges a p/n-junction 115 at a single instance. This impingement creates a single electron-hole pair in p/n-junction 115. However, as shown in FIG. 1, unabsorbed photons 120 reflect into the atmosphere or space.
Conventional single solar cells are typically small wafers approximately six inches across. These solar cells may be first arranged into modules and then large photovoltaic arrays that may cover dozens of square meters in order to satisfy specific power needs.
Thus, the conventional strategy is to absorb energy from light photons that impinge a solar cell at a single impingement instance. Then energy from this single impingement is then converted to an electrical current by the solar cell. This often causes problems because the conventional strategy absorbs only a small amount of the available energy. For example, the conventional strategy reflects unabsorbed energy into the atmosphere or space.